1. Field of the Invention
The present invention relates to a recording/reproduction apparatus that has a file system and executes the data required real-time recording/reproduction processing. In particular, the present invention relates to a recording/reproduction apparatus having a mechanism for managing an operation log of a file system and synchronization of metadata at the time of a the data required real-time recording/reproduction operation, a recording/reproduction method executed by the recording/reproduction apparatus, and a recording/reproduction program for causing the recording/reproduction apparatus to execute recording/reproduction processing.
2. Description of Related Art
As a recording/reproduction apparatus that executes video recording processing and reproduction processing, there has conventionally been known a recording/reproduction apparatus having a construction where video writing (recording processing) and reading (reproduction processing) are distinguished from each other. For instance, in JP 11-69279 A (see FIGS. 1 to 3 of that document) Patent document 1, there is disclosed a technique with which in a recording/reproduction apparatus that simultaneously performs recording and reproduction of multiple pieces of video data, a queue is provided for each of writing and reading and the queue on a writing side is controlled with a higher priority, thereby eliminating a failure on a recording side.
Also, for instance, in JP 2001-309333 A (Patent Document 2), there is disclosed a technique with which in a video server that utilizes a disk array or the like, band allocation is managed, the transfer of real-time data between apparatuses is realized, the real-time data transfer of a video or the like is distinguished from the transfer of data that does not require a real-time property, and the band allocation is performed based on a result of the distinguishing.
The recording/reproduction apparatus disclosed in Patent Document 1 performs processing without distinguishing among various kinds of processing such as logging concerning a recording operation and writing of metadata for file management. Consequently, it is impossible to manage the degree of an I/O load imposed by the management of information other than video data midway through a video recording operation.
Also, in Patent Document 2, no description is given concerning metadata necessary for file management, management of an execution timing thereof, and the like, and there does not exist an idea that a load is suppressed based on a parameter concerning a processing request frequency in an operation such as video recording/reproduction.
Meanwhile, it is conceivable that there frequently occurs a situation where a recording/reproduction apparatus used in an ordinary household is powered off during execution of recording/reproduction processing, and it is impossible to avoid a possibility that data will be lost due to such a situation. As a countermeasure against such a problem, there is generally performed establishment of synchronization or logging of input/output operations (recording of contents of executed operations).
Accordingly, input/output operations accompanying the synchronization operation or the log generation are frequently performed, so that particularly in the case of a recording/reproduction apparatus for an optical disk or the like whose random access performance is low, considerable time is consumed by the input/output operations. Consequently, there occurs a problem that processing performance concerning video data is lowered due to an influence of the input/output operations accompanying the synchronization operation or the log generation.
The present invention addresses and seeks to solve, at least in part the problems described above and making it possible, in a recording/reproduction apparatus, such as an optical disk recorder, whose random access performance is low, to adjust a processing time consumed by a synchronization operation or log generation and to improve the reliability of the apparatus without causing a lowering of the processing performance.
Also, the present invention is aimed at making it possible, in a recording reproduction apparatus, such as an optical disk recorder, whose random access performance is low, to enable I/O scheduling based on importance of data, and consequently to increase processing efficiency under an environment where the recording/reproduction processing of information, such as a video, coexists with the input/output of another file to improve the function of the apparatus.